Intramedullary, periosteal, and extraskeletal Ewing sarcomas: retrospective study of a series of 126 cases in a reference center

Periosteal Ewing Sarcoma with Distant Metastases: Report of Two Patients and Review of the Literature

Periosteal Ewing sarcoma (ES) is an exceedingly rare topographic subtype of the ES. To our knowledge, only 60 patients have been reported in the medical English language literature. It predominantly affects men in the second decade of life and arises in the long tubular bone diaphysis. PES rarely develops distant metastases. We report two patients of this rare ES location that were found on the distal tibial shaft and proximal femoral diaphysis of a 21-year-old man and an 8-year-old boy, respectively. Both patients were treated with neoadjuvant chemotherapy, wide resection, and adjuvant chemotherapy. One of our patients had lung metastases at the time of diagnosis and died 5 years later. The other patient presented intramedullary humeral bone metastasis 19 years after diagnosis. There has been no evidence of disease in the 26 years of follow-up. Close follow-up of periosteal ES is recommended because distant metastases may exceptionally occur, even several years after diagnosis.

Spontaneously regressive multifocal bone pseudomyogenic hemangioendothelioma in a 17-year-old boy: a case report

Pseudomyogenic hemangioendothelioma (PMH) is a rare vascular tumor that occurs in young mostly male patients. Seventy percent of PMH cases are multifocal and 25% involve bones. PMH is an indolent tumor with mild local aggressiveness and an unclear pathology. Only two cases of spontaneous regressive bone PMH have been reported. Here, we report the case of a 17-year-old boy with a multifocal bone PMH diagnosed from a chronic pain in his left knee. The PMH affected the right scapula, both humeri, the right olecranon, the second metacarpal bone, the second and fourth right ribs, the thoracic and lumbar spine, the pelvic ring, the left and right femoral neck, and the left patella. Every lesion presented with a lobulated, lytic pattern, sometimes with a peripheral sclerotic rim. MRI showed a tissue lesion with a low intensity on T1-weighted sequences and high intensity on T2-weighted sequences. Enhancement of T1 gadolinium fat-saturated sequences was bright. After discussion, a national specialized board decided to actively monitor the patient and start general chemotherapy in the case of progression. The disease was stable at 3 and 6 months and showed signs of regression at 1 year, which was further confirmed at 2 years. CT scan and MRI highlighted a progressive filling of the tumor with cancellous bone and a regression of the tissue contingent. This case report highlights to a new therapeutic approach for indolent PMH that does not prevent further treatment in the case of progression.